1. Technical Field
The present invention relates to an electro-optical device, an electronic apparatus, and a method of manufacturing an electro-optical device, and more particularly, to an electro-optical device including an electro-optical device substrate having capacitive elements, each composed of a pair of electrodes and an insulating film interposed therebetween, formed thereon, to an electronic apparatus, and to a method of manufacturing an electro-optical device.
2. Related Art
There has been known a liquid crystal device, which is an example of an electro-optical device, that includes pixel electrodes arranged in a matrix and thin film transistors (hereinafter, referred to as TFTs) connected to the pixel electrodes and is driven by an active matrix driving method. The liquid crystal device, which is an example of the electro-optical device, includes a TFT array substrate, a counter substrate arranged opposite to the TFT array substrate, the pixel electrodes formed on the TFT array substrate, a counter electrode formed on the counter substrate so as to be opposite to the pixel electrodes, a liquid crystal layer interposed between the pixel electrodes and the counter electrode, and capacitive elements connected to the pixel electrodes and the TFTs. The arrangement of liquid crystal molecules in the liquid crystal layer is changed according to a potential applied between the pixel electrodes and the counter electrode, which causes transmittance of light passing through the liquid crystal layer to vary, thereby displaying an image.
In this case, the capacitive elements connected to the TFTs function to improve the potential holding characteristic of the pixel electrodes.
The substrate of the electro-optical device includes an image display region having scanning lines, data lines, the pixel electrodes, and storage capacitors, which are the capacitive elements, provided therein, a scanning line driving circuit, and a data line driving circuit. An electro-optical device disclosed in JP-A-2004-191930 can be considered as a typical example of the above-mentioned electro-optical device.
The storage capacitor, which is the capacitive element, includes a lower electrode electrically connected to the TFT and the pixel electrode, a capacitor electrode arranged opposite to the lower electrode, and a dielectric film arranged between the lower electrode and the capacitor electrode. It is necessary to increase the capacitance of the capacitive element in order to improve the display quality of the electro-optical device. In recent years, a method of reducing the thickness of the dielectric film of the capacitive element has been used. In addition, in order to increase the capacitance of the capacitive element, for example, a method of three-dimensionally forming the capacitive element to increase the area of the capacitive element, such as a method of forming the capacitive element in a contact hole, has been used.
However, when the thickness of the dielectric film decreases and the capacitive element is three-dimensionally formed to improve the display quality of the electro-optical device, an electric field may concentrate on a portion in which a side surface and an upper surface of a step portion, such as an aperture of the contact hole, intersects each other, that is, on the lower electrode formed on an angular portion. Therefore, in the conventional electro-optical device having the above-mentioned structure, a short circuit may occur between the lower electrode and the capacitor electrode of the capacitive element. When the shirt circuit between the electrodes of the capacitive element occurs in a pixel, the pixel causes a constant potential to be always applied to the liquid crystal layer. Thus, the related art has a problem in that the manufacturing yield of the electro-optical device is lowered.